Hydrodynamic condition and response of formation water chemical fields of geothermal water in North China Basin

The hydrogeochemical zonations of geothermal water in North China Basin can be used to indicate the hydrodynamic zoning because the latter actively responded to the former. The quality of geothermal water is deteriorating and the deuterium-excess parameter decreases from surrounding mountains to the basin and from shallow to depth in North China Basin, suggesting that the rate of groundwater circulation become slower and slower. The distribution characteristics of high salinity zoning of geothermal water indicate that the Taihang Mountains and Yanshan Mountains in the west and north are predominant recharge area of geothermal water in North China Basin, while a small recharge amount is from the mountains in the southwest of Shandong Province. In addition, whether in the horizontal or vertical direction in the basin, the hydrogeochemical zonations also indicate that there is hydrodynamic equilibrium zone between the centripetal flow (infiltration original water) and acentric flow (sedimentary original water) of geothermal water in sandstone. This indicates that there is transient equilibrium between the centripetal flow and the acentric flow. © 2015, Editorial Office of Earth Science Frontiers. All right reserved.